Explain these Hip-Hop lyrics

Cafe Society
1

The song is called “Tippin’ Dominos” and it’s on the album Gettin’ Jukie Wid It by RJD2. The lyricist in this case is Vast Aire.

The refrain goes like this:

“The same motion, that moves the hip
Has the same effect on dominoes when tipped
I got two forty-five cents embedded
And I won’t hesitate to leave your crew shredded”
I’m assuming the “two forty-five cents” are pistols, but I don’t really get the rest. Can anyone decipher?
While I’m at it, let me just say that this is just an amazing album, though rare and a bit hard to find. If you like RJD2’s beats as well as rap from Cannibal Ox, Soul Position, Aesop Rock, Souls Of Mischief, and the like, definitely try to find it. It has what is now probably by all time favorite rap song – The F-Word (Remix)

2

Let me put it this way: Does the phrase “tipping dominoes” mean anything other than the literal?

3

I’m no hiphop expert, but ‘tippin dominoes’ just sounds like slang for sex. Not sure why.

4

It sounds to me like he (they?) is saying that if some third party screws around with his girl, everything between him and the third party is over and he’ll kill them.

But I rarely listen to hip-hop, so what do I know?